Newsgroups: comp.lang.c++,comp.lang.smalltalk,comp.lang.eiffel,comp.lang.ada,comp.object
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news.dfci.harvard.edu!camelot.ccs.neu.edu!nntp.neu.edu!grapevine.lcs.mit.edu!bloom-beacon.mit.edu!howland.erols.net!news.mathworks.com!uunet!in2.uu.net!uucp5.uu.net!alexandria.organon.com!alexandria!jsa
From: jsa@alexandria (Jon S Anthony)
Subject: Re: OO, C++, and something much better!
In-Reply-To: Alan Lovejoy's message of Sat, 01 Feb 1997 12:04:52 -0800
Message-ID: <JSA.97Feb3175743@alexandria>
Sender: news@organon.com (news)
Organization: Organon Motives, Inc.
References: <JSA.97Jan16141937@alexandria> <E44u82.6uB@syd.csa.com.au>
	<mheaney-ya023280001601972303180001@news.ni.net>
	<32DF458F.4D5C@concentric.net> <32DF94DC.6FF8@watson.ibm.com>
	<32DFD972.37E4@concentric.net> <5bphq4$5js@mulga.cs.mu.OZ.AU>
	<32E05FAF.47BA@concentric.net> <5buodl$bci@boursy.news.erols.com>
	<32E2FEC7.2F7B@concentric.net> <5bvncj$gqg$1@A-abe.resnet.ucsb.edu>
	<32E47B4B.56D9@concentric.net> <32E4E6E1.437E@dstsystems.com>
	<32EE858E.FAD@concentric.net> <5cobea$cm8@news1.ucsd.edu>
	<32F07705.289C@concentric.net> <JSA.97Jan30205754@alexandria>
	<32F3A1E4.2F6@concentric.net>
Date: Mon, 3 Feb 1997 22:57:43 GMT
Lines: 39
Xref: glinda.oz.cs.cmu.edu comp.lang.c++:245253 comp.lang.smalltalk:50840 comp.lang.eiffel:18161 comp.lang.ada:57115 comp.object:60783

In article <32F3A1E4.2F6@concentric.net> Alan Lovejoy <alovejoy@concentric.net> writes:

> > There are several other ways of doing this, depending on what you are
> > fishing for, which have various tradeoffs and flexibilities.  Shrug.
> 
> Unless "D1 := D2" is a legal assignment, your example falls short of 
> what I was asking for (and perhaps even then, but I'm not fluent enough
> in Ada95 to be sure).

Well, as I pointed out (up there) depending on what it is you really
_want_ there are various ways of doing this.  Ones which would in fact
allow the "D1 := D2" assignment.  But they start to become _very_ odd
- as in you begin to lose pretty much most of the statically checkable
aspects and just keep pushing more and more off to runtime checks.
The problem is, there is no good reason that I can see for _why_ you
would _want_ to do this sort of thing.


> The example from Transframe given by David Shang appears to be **much**
> closer--and much more elegant.

Could be.  Haven't seen it, but have seen others and it does have have
more obvious flexibility here.


> > Does the above answer yours????
> 
> Apparently not.

Well, it is hard to answer when you don't have a clear question...

/Jon
-- 
Jon Anthony
Organon Motives, Inc.
Belmont, MA 02178
617.484.3383
jsa@organon.com

